The present invention relates to a distributed control system comprising a plurality of controllers, a program apparatus, and man-machine systems, which are all interconnected by a network and, more specifically, relates to a configuring method including for achieving optimal configuration of large scale control systems.
In a known method for providing programming for a plurality of controllers, system designers define the specification of the macro programs to be executed in the individual controllers on the basis of the expected load rate and of the expected traffic quantity of the network. The designers then further breakdown the specification in terms of the description of the macro programs.
In order to achieve a concrete and visible grasp of the control status of the operated systems, the network monitors and CPU monitors are connected outside the operated system, and the load rate and the traffic quantity of the network are detected individually.
In the above prior art systems, there is no serious problem in the case of small-scale distributed systems having a small number of controllers. In the case of large-scale distributed systems having a large number of controllers, however, there results a problem of overhead for realizing optimal decision for macro programs to be executed in the individual controllers.
In addition, in the prior art, in view of system performance including a balanced distribution of the load rate across the controllers and a minimization of the access occurrence of the network traffic, there is no guarantee that human judgment regarding the allotment of macro programs will reach optimal levels.
Even if the controlled object is determined explicitly, because the number of controllers required for controlling these objects cannot be determined quickly, a large amount of time is spent for specification definition of the distributed systems.
And furthermore, in the actual operation of the distributed control systems after their installation, as the above mentioned external apparatus are necessary for detecting the load rate of the arithmetic unit and the network traffic, the cost of the system increases.
Finally, in the prior art, due to the system performance limitations, the allotment of the control programs cannot be changed dynamically so as to estimate the overall status of the system under operation and optimize the system operation.
The above mentioned problem can be resolved by the following technical means.